The impeller according to the present invention may be used for various applications, for example, for moving air through a heat exchanger or radiator of an engine cooling system for a vehicle or similar apparatus; or for moving air through a heat exchanger for heating equipment and/or through air conditioning evaporators used in vehicle cabins.
Furthermore, the impeller according to the present invention may be used to move air in fixed air conditioning or heating equipment in homes.
Impellers of this type must meet various requirements, including: low noise, high efficiency, compact size, ability to achieve good head (or pressure) values and flow.
In order obtain a good flow of air by using impellers whose dimensions are small, it may be necessary to extend the blades towards the centre of the impeller itself, thereby increasing the flow in the central portion.
An impeller of this type is described in U.S. Pat. No. 6,126,395; its compact impeller features an extension of the blades towards the centre of the impeller, the blades are connected and overlap a hub.
The latter presents a curved area containing the stator of the actuator motor, while each blade contains a permanent magnet that works with the stator in order to create the torque necessary for rotation.
Due to the structure of the hub surrounding the stator it is difficult to change the type and size of the motor that rotationally drives the impeller.
Depending on the type of application and in order to obtain the best performance, it may be necessary to fit impellers of a certain size with electric motors of different sizes and power ratings.
In particular, to meet standardization requirements, it may be necessary to use motors with diameters that are relatively wide on impellers that are compact in size.